Boston Scientific announces positive data from largest data set in interventional treatment of pulmonary embolism

MedTech News: Boston Scientific announced positive results for the EkoSonic Endovascular System (EKOS system) during a late-breaking clinical trial presentation at the recent Vascular InterVentional Advances (VIVA) meeting.

The KNOCOUT PE registry was designed to understand the changing protocols used with ultrasound-facilitated, catheter-directed thrombolysis as standard of care in the treatment of acute pulmonary embolism (PE) and associated patient outcomes after publication of the OPTALYSE PE study. The OPTALYSE PE study demonstrated that the EkoSonic endovascular system (EKOS) is effective in the treatment of acute intermediate-risk PE using lower thrombolytic doses and shorter duration of infusion.

“PE remains a life-threatening and complex disease, but these results provide an opportunity to advance patient care by showcasing evidence that proves a lower drug dose and shorter infusion duration of a thrombolytic agent may result in enhanced safety and efficacy,” said Dr Keith Sterling, Inova Alexandria Hospital, Alexandria, VA, study principal investigator. “The findings in this registry analysis are very reassuring to physicians making critical evidence-based decisions for their patients in what are oftentimes emergent treatment situations.” 

This study involved 83 international sites and enrolled 489 and 991 patients in prospective and retrospective cohorts, respectively. This report highlights results from the prospective registry. Patients with acute intermediate–high-risk or high-risk PE and treated with EKOS acoustic pulse thrombolysis were enrolled between March 2018 and June 2020.

The mean recombinant tissue plasminogen activator (rtPA) infusion duration was 10.4 hours, and the mean total rtPA dose was 17.9 mg, with 32.4% of patients receiving ≤ 12 mg of rtPA. The mean percent reduction in right ventricular/left ventricular (RV/LV) ratio from baseline to post-procedure was 22.6%. This statistically significant reduction in RV/LV was maintained over time. There was a significant improvement in quality of life, with a 41.1% reduction in PEmb-QoL (Pulmonary Embolism Quality of Life Questionnaire) score by 3 months post-procedure. Major bleeding events within 30 days of the procedure, as defined by the International Society on Thrombosis and Haemostasis bleeding scale, occurred in 2.5% (12/489) of patients in the prospective cohort. No intracerebral haemorrhagic events were reported.

“As the largest prospective body of evidence in the interventional PE space to date, the KNOCOUT PE registry provides an accurate modern representation of patients with PE treated with the EKOS system every day,” said Michael Jaff, chief medical officer and vice president clinical affairs, technology and innovation, Peripheral Interventions, Boston Scientific. “The strong safety and efficacy findings exhibited in this registry add to the existing clinical evidence supporting the EKOS system as a treatment option that physicians can trust, as it is already the most studied interventional device in the PE space.”

Results from this prospective multicentre registry reflect contemporary practice and demonstrate the performance of EKOS in the management of acute PE, with lower total rtPA dose and shorter infusion duration, marked clinical improvement in RV/LV ratio, low rates of major haemorrhagic complications with no intracerebral haemorrhagic events, and improvement in PE-specific quality of life.